/*
 * Licensed to the Apache Software Foundation (ASF) under one or more
 * contributor license agreements.  See the NOTICE file distributed with
 * this work for additional information regarding copyright ownership.
 * The ASF licenses this file to You under the Apache License, Version 2.0
 * (the "License"); you may not use this file except in compliance with
 * the License.  You may obtain a copy of the License at
 *
 *      http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */
package org.apache.tomcat.websocket;

import org.apache.tomcat.util.res.StringManager;

import javax.websocket.Extension;
import java.util.List;

public class TransformationFactory {

	private static final StringManager sm = StringManager.getManager(Constants.PACKAGE_NAME);

	private static final TransformationFactory factory = new TransformationFactory();

	private TransformationFactory() {
		// Hide default constructor
	}

	public static TransformationFactory getInstance() {
		return factory;
	}

	public Transformation create(String name, List<List<Extension.Parameter>> preferences,
	                             boolean isServer) {
		if (PerMessageDeflate.NAME.equals(name)) {
			return PerMessageDeflate.negotiate(preferences, isServer);
		}
		if (Constants.ALLOW_UNSUPPORTED_EXTENSIONS) {
			return null;
		} else {
			throw new IllegalArgumentException(
					sm.getString("transformerFactory.unsupportedExtension", name));
		}
	}
}
